1. Field of the Invention
The present invention relates to a method of controlling a communication system.
2. Description of the Related Art
Conventionally, image forming apparatuses having a server function, such as that of a Web server, a file server, or the like, have appeared, and it has become possible to use the server function of this kind of image forming apparatus from a remote terminal via a network. One of these kinds of server functions is a VNC (Virtual Network Computing) server. A remote terminal is able to display screens, on a display module of the terminal, of an operation panel of an image forming apparatus by using an application referred to as a VNC viewer for the image forming apparatus having a VNC server function. With this, a user of the terminal is able to operate the operation panel of the image forming apparatus with the same feeling as being in the place that the image forming apparatus is located.
Also, in order to make the VNC viewer unnecessary, conversion software for converting between an HTTP (Hypertext Transfer Protocol) and the VNC protocol exists. When the conversion software is used, it is possible to display a screen of an operation panel of an image forming apparatus on a general Web browser, and to operate the image forming apparatus via the screen without installing a VNC viewer on the remote terminal.
In Japanese Patent Laid-Open No. 2010-157240, a technique is recited in which when a request for a screen acquisition is transmitted by an HTTP to a gateway from a PC, the gateway acquires screen information from an image forming apparatus by the VNC protocol, and returns the screen information to the PC by the HTTP. With this kind of technique, an administrator of the image forming apparatus can confirm a status of the image forming apparatus from a PC at his or her own seat without going to the place that the image forming apparatus is located in an office.
However, in the conventional configuration, it is necessary to establish a connection to a VNC server from a VNC viewer, conversion software, or the like. For this reason, in an environment in which an image forming apparatus having a VNC server exists inside a firewall, a VNC viewer, conversion software, or the like, on the Internet could not connect with the image forming apparatus. This is because the firewall is configured so as to reject connections to internal terminals from the outside, and so VNC viewers, conversion software, or the like on the Internet, could not establish a connection with the VNC server of the image forming apparatus. For this reason, there was no way for a serviceman of the image forming apparatus to confirm the status by connecting to the VNC server of the image forming apparatus of a customer.